PromptLayer

What is PromptLayer?

PromptLayer is a platform for managing prompts, evaluating changes and watching LLM applications run in production. Teams keep prompts in a registry outside the codebase, edit them in a visual editor, compare versions, and publish a chosen version to dev or prod without an application redeploy. Dataset-backed evaluations, regression tests, human review and automated graders check a change before users see it. On the observability side, PromptLayer logs requests, traces agent runs, and ties each log back to the prompt version that produced it, with cost, latency and token usage tracked alongside. Its design is non-proxy and it supports OpenTelemetry spans around model calls. Product managers, lawyers, teachers and other subject experts can iterate on prompts without waiting on engineers. PromptLayer pricing starts with a free plan at $0 per month, then Pro at $49 per month and Team at $500 per month, plus a custom Enterprise plan with self-hosting options.

Use cases

• Version and deploy prompts without a redeploy
• Run regression evals on prompt changes
• Trace multi-step agents in production
• Track LLM cost, latency and token usage
• A/B test new prompt versions gradually
• Compare prompts across different models
• Let domain experts edit prompts visually

Who it's for

• AI engineers
• Product managers
• Domain experts
• Prompt engineers
• Enterprise AI teams

Why use PromptLayer

• Keeping prompts out of application code lets teams change model behavior without waiting for an engineering release.
• Subject experts such as lawyers, teachers and content staff can edit and test prompts directly in the dashboard.
• Regression evals run on each prompt update, so quality drops show up before a version goes live.
• Each production log links to the exact prompt version behind it, which makes it quick to trace a bad output to its cause.
• Pricing is tiered, with a free plan for small experiments and usage-based overage rates as volume grows.

PromptLayer features

• No-code visual prompt editor and prompt registry
• Version history with comments, diffs and rollbacks
• Separate dev and prod prompt deployments
• A/B testing of prompt versions with metric comparison
• Dataset evaluations with human and AI graders
• Regression tests triggered whenever a prompt updates
• Request logs with metadata, scores and custom key-value pairs
• Agent tracing with OpenTelemetry span support
• Cost, latency and token usage analytics per prompt version
• SDK and REST API for logging from any language

PromptLayer integrations

• OpenTelemetry

How to get started with PromptLayer

1. Sign up and connect your LLM application using the PromptLayer SDK or REST API so requests are logged.
2. Move your prompts into the registry and refine them in the visual editor, saving versions with notes.
3. Build datasets and evaluation runs, with human or AI graders, to test each version against real examples.
4. Publish the approved version to dev or prod, optionally releasing it gradually to compare metrics.
5. Watch traces, cost, latency and failures in production, then feed what you learn back into the next edit.

PromptLayer limitations

• Free plan: 5 users, 2.5k requests per month and 10MB per dataset
• Free, Pro and Team plans run on PromptLayer's US cloud only
• Self-hosting and EU cloud hosting are Enterprise options
• Usage beyond plan limits is charged per transaction

PromptLayer pricing

Yes, PromptLayer has a free plan. Paid plans start at $49 per month, according to the official pricing page on 24 Oct 2026.

PromptLayer plans

• Free

  $0

  per month

  • 5 users
  • 2.5k/month requests
  • 1 workspace
  • 250/month eval cell executions
  • 10MB max per dataset

• Pro

  $49

  per month

  • Same limits as Free
  • Unlimited playgrounds
  • Unlimited workspaces
  • 150MB max per dataset
  • Pay-as-you-go at $0.003 per txn

• Team

  $500

  per month

  • 25 users
  • 100k+/month requests
  • 7.5k+/month eval cell executions
  • 1GB max per dataset
  • Pay-as-you-go at $0.002 per txn

• Enterprise

  Custom

  • Custom limits on everything
  • Role-based access controls
  • Deployment approvals
  • HIPAA with BAA
  • Flexible hosting options
  • Dedicated support
  • Data retention control

Plans as listed on the official pricing page on 24 Oct 2026. Prices can change and may vary by country or exclude tax. Check the official pricing page.

PromptLayer alternatives

The main PromptLayer alternatives listed on Debuly are Langfuse, Braintrust, Helicone, Lunary, PromptHub and OpenLIT. The table compares pricing and platforms; order is A–Z.

1. 

   Braintrust

   AI observability and evaluation platform for tracing LLM apps and agents, scoring outputs and catching regressions before release.

   Developer platformsCoding
   FreemiumVisit Braintrust (official site)
2. 

   Helicone

   Open-source LLM observability and AI gateway that logs requests, tracks cost and latency, and routes to 100+ models through one API.

   Developer platformsCoding
   FreemiumVisit Helicone (official site)
3. 

   Langfuse

   Open-source LLM observability and evaluation platform for tracing agents, managing prompts and scoring outputs.

   Developer platformsAutomation and agentsCoding
   FreemiumVisit Langfuse (official site)
4. 

   Lunary

   LLM observability and evaluation platform for logging calls, tracing agents, managing prompts and running evaluations.

   Developer platformsAutomation and agentsCoding
   PaidVisit Lunary (official site)
5. 

   OpenLIT

   Open-source, OpenTelemetry-native platform for tracing, evaluating and guarding AI agents, with cost and GPU monitoring

   Developer platformsCodingAutomation and agents
   Open sourceVisit OpenLIT (official site)
6. 

   PromptHub

   Prompt management platform for teams with Git-style versioning, a playground, evaluations, CI pipelines and a prompt API.

   Developer platformsWritingAutomation and agents
   FreemiumVisit PromptHub (official site)

PromptLayer FAQ

Sources & verification

Facts on this page come from the official sources below, each with the date we read it. Written by Debuly; the vendor did not review this page.

Image credits

• Logo: from promptlayer.com · fetched 24 Oct 2026 · Vendor trademark, used only to identify the product; removed on request
• Cover: none collected yet, so a generated tile is shown.

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